During small incision surgery, and particularly during ophthalmic surgery, small probes are inserted into the operative site to cut, remove, or otherwise manipulate tissue. During these surgical procedures, fluid is typically infused into the eye using an infusion system, and the infusion fluid and tissue are aspirated from the surgical site using an aspiration system. The infusion and aspiration systems must be primed prior to surgery. Gas can become trapped within the infusion system and the aspiration system, which can cause certain problems. In prior systems, the system and method of priming the surgical cassette did not remove the trapped gas from the systems. Therefore, a need continues to exist for an improved system and method of priming a surgical cassette.